HFIT provides high frequency (HF) impulses to the spinal cord and dorsal root ganglia for stimulation that reduces nociceptors, inhibits neuroinflammatory mediator release, and thus alleviates pain.
HFIT stands in stark contrast to conventional SCS which often produces paresthesia; instead it completely forgoing this effect. Clinical trials have demonstrated significant improvements in outcomes such as 6MWT, ODI and pain relief measured on visual analogue scales.
Physiological Effects
High-frequency impulse therapy (HFES) is an evidence-based noninvasive, pharmacologically independent pain management technology. Studies have proven its efficacy against chronic musculoskeletal conditions like sciatica, Failed Back Surgery Syndrome, and Complex Regional Pain Syndrome.
HFES stimulates the spinal cord by inducing neurochemical changes that inhibit pain signals from reaching the brain, and by activating natural painkillers like endorphins to counteract and mask painful sensations. Furthermore, it can target C-fiber nerves responsible for transmitting generalized pain sensations, thus interrupting their action by disrupting pain signaling processes.
An animal study demonstrated how HFES inhibits nociceptor neuroinflammatory mediator release. These results suggest HFES may reset sensory neurons into less pro-inflammatory states and attenuate hyperalgesia related to nociceptor activation or peripheral injury.
Research was performed on a small group of volunteers suffering from chronic low back pain. Participants were randomly divided into two groups and randomly assigned one of two treatments – TCS only or both TCS and BURST for three months; both groups experienced improvements in symptoms but only the TCS group saw an effective reduction in pain intensity.
This was the first randomized controlled trial comparing HFES and TCS in terms of chronic low back pain relief. The results indicate that HFES is highly effective noninvasive pain management technique with few side effects and fewer drug-related complications than traditional pharmacological therapies; furthermore it could become part of multisource systems capable of providing different SCS waveforms depending on clinical outcome.
Research was carried out at the University of Poitiers and Niort and La Rochelle Hospitals in France, enrolling patients who scored 5 or higher on a visual analogue scale for chronic low back pain, randomly assigning them one of six arms containing TCS, BURST or HF for three-month trials, which would allow each arm to establish its preferred waveform over time.
Clinical Effects
High frequency impulse therapy (HFIT) is an efficient and safe solution to chronic pain management, often used in treating conditions like fibromyalgia, shingles, back pain and rheumatoid arthritis. It works by blocking pain signals sent from c-fibers to reduce their intensity and duration. Neuragenex uses an FDA-cleared device to stimulate endorphin production in the brain, producing natural painkillers which create feelings of relaxation and well-being. Our medical provider administers this treatment. Electric pulses are applied directly to affected areas for pain management. Studies have proven their efficacy as an alternative to opioids for managing chronic pain and can significantly decrease post-operative opioid needs and side effects.
Animal models have demonstrated that HFES therapy can successfully alleviate neuropathic pain by inhibiting neuroinflammation. Neuroinflammation contributes to neuropathic discomfort through the release of molecules such as calcitonin gene-related peptide (CGRP), substance P, and high mobility group box 1 protein (HMGB1). By blocking sensory neuron secretory activity by modulating these molecules, HFES blocks secretory activity thereby alleviating neuropathic discomfort.
Hand-held stimulators like the ENSO HFIT can deliver HFES treatments for pain management at home, in social settings or while exercising. Patients can control how long and the strength of stimulation sessions by pairing their phone to their device – giving them complete control of how it’s used and used out. It allows patients to manage their discomfort from anywhere at any time and place.
Clinical tests of the ENSO HFIT demonstrate a substantial decrease in neuropathic pain over placebo, with 63% of 62 patients who underwent trial implants of low dorsal spinal cord stimulation achieving positive VAS scores at one month after trial installation and 77% reaching this milestone by six months post permanent installation.
Future work must focus on the establishment of effective peripheral nerve stimulation protocols which depend on the pathology intended to be treated. Timing, frequency and waveform considerations for high frequency electrical stimulation (HFES) therapy must all be thoroughly explored so as to maximize effect on target sensory nerves.
Safety
Electrical stimulation therapy is a noninvasive, drug-free therapy generally considered safe for most patients. However, e-stim therapy should not be utilized by people with implanted medical devices such as pacemakers or hearing aids as electrical pulses could interfere with their normal functionality and cause irritation or other side effects if placed too close to nerves.
Studies have demonstrated the efficacy of TCS to significantly alleviate pain. It works by blocking transmission of painful impulses in the brain by creating an intermittent tingling sensation known as paresthesia which covers up the actual signal of discomfort. Some SCS devices allow users to select an “anti-paresthesia setting” which eliminates paresthesia while still masking discomfort.
BURST and HF waveforms have been demonstrated to augment TCS pain relief without inducing paraesthesia sensations; however, previous studies only included TCS as part of the comparisons.
The MULTIWAVE study is the first comprehensive comparison between these three modalities in one device over a 3-month period, providing evidence of their efficacy independent of any paraesthetic effect.
This will also mark the first time TCS and BURST are compared together using Illumina3D(tm), an algorithm for model-guided anatomically guided 3D neural targeting programming.
Illumina3D(tm) is an advanced software program that utilizes data sources such as patient clinical history and pain mapping to create a personalized neurotargeting map. This model then serves to optimize anodic and cathodic current distribution in stimulation lead contacts to define individual patients’ anatomical “sweet spots.”
This software will also determine the optimal frequency, pulse width and amplitude for an SCS device, so a doctor can adjust these settings as per each patient’s individual needs during follow-up visits. Stimulation only reduces pain by changing how the brain interprets painful stimuli – it does not remove their source. Whether 50-70% reduction of pain will occur depends entirely on individual response but is estimated as being on average 50-70%.
Conclusions
HF-TENS therapy appears to be successful at alleviating experimental heat pain in young subjects and may do so by suppressing neuroinflammatory mediator release by sensory neurons. This finding lends credence to the theory that HF-TENS may alleviate clinical pain by restricting molecular mediator release that contribute to chronic neuroinflammatory processes in chronic neuropathic states.
Furthermore, HF-TENS’ ability to increase pain thresholds has also been demonstrated, offering hope of alleviating chronic discomfort through non-noxious stimuli like TCS or LF-TENS which would normally masked them. This finding shows HF-TENS’ potential as an effective means for dealing with non-noxious stimuli induced pain than traditional TCS or LF-TENS methods.
The MULTIWAVE study seeks to compare TCS, BURST and HF SCS waveforms in an randomized controlled cross-over trial in implanted patients suffering from chronic refractory FBSS. The MULTIWAVE device has the unique capability of independently and simultaneously testing all three waveforms within 24 hours – an ability which should increase patient compliance and allow selecting of therapeutic options which offer superior symptom relief.
This new design provides the opportunity to study a new generation of SCS devices capable of providing high frequency (HF) stimulation. HF stimulation has been demonstrated to produce paraesthesia-free and more selective effects for treating axial back pain compared to TCS which tends to stimulate dorsal root ganglia and peripheral nerves of lower extremities. HF has frequency ranges between 500Hz to 10kHz with amplitudes between 60-67% of pain threshold.
High frequency impulse therapy provides an alternative non-pharmacological method of pain relief that does not lead to addiction and life style changes with undesirable side effects. MSK solutions that include this non-invasive, minimally invasive treatment should experience increasing market success; however it is vitally important that their care models match up against published research studies; currently available research is only exploratory and requires further validation.